Buggy code:
public class TCLogParser implements LogParser { static Logger log = LoggingManager . getLoggerForClass ( ) ; public static final String GET = "GET" ; public static final String POST = "POST" ; protected String RMETHOD = null ; protected String URL_PATH = null ; protected boolean useFILE = true ; protected File SOURCE = null ; protected String FILENAME = null ; protected BufferedReader READER = null ; protected Filter FILTER = null ; public TCLogParser ( ) { } public TCLogParser ( String source ) { } public void setUseParsedFile ( boolean file ) { } public void setFilter ( Filter filter ) { } public void setSourceFile ( String source ) { } public File openFile ( String filename ) { } public int parse ( TestElement el , int parseCount ) { } public int parseAndConfigure ( int count , TestElement el ) { } protected int parse ( BufferedReader breader , TestElement el , int parseCount ) { } protected int parseLine ( String line , TestElement el ) { int count = 0 ; String cleanedLine = this . cleanURL ( line ) ; TCLogParser . log . debug ( ( "parsing<seq2seq4repair_space>line:<seq2seq4repair_space>" + line ) ) ; el . setProperty ( METHOD , RMETHOD ) ; if ( ( FILTER ) != null ) { TCLogParser . log . debug ( "filter<seq2seq4repair_space>is<seq2seq4repair_space>not<seq2seq4repair_space>null" ) ; <START_BUG> if ( ! ( FILTER . isFiltered ( line ) ) ) { <END_BUG> TCLogParser . log . debug ( "line<seq2seq4repair_space>was<seq2seq4repair_space>not<seq2seq4repair_space>filtered" ) ; count ++ ; line = FILTER . filter ( cleanedLine ) ; if ( line != null ) { createUrl ( cleanedLine , el ) ; } } else { TCLogParser . log . debug ( "Line<seq2seq4repair_space>was<seq2seq4repair_space>filtered" ) ; } } else { TCLogParser . log . debug ( "filter<seq2seq4repair_space>was<seq2seq4repair_space>null" ) ; count ++ ; createUrl ( cleanedLine , el ) ; } return count ; } private void createUrl ( String line , TestElement el ) { } public String cleanURL ( String entry ) { } public boolean checkMethod ( String text ) { } public String stripFile ( String url , TestElement el ) { } public boolean checkURL ( String url ) { } public boolean checkParamFormat ( String text ) { } public void convertStringToJMRequest ( String text , TestElement el ) { } public NVPair [ ] convertStringtoNVPair ( String stringparams ) { } protected NVPair parseOneParameter ( String parameter ) { } protected Vector parseParameters ( String parameters ) { } public StringTokenizer tokenize ( String line , String delim ) { } public void close ( ) { } public static class Test extends JMeterTestCase { private static final TCLogParser tclp = new TCLogParser ( ) ; private static final String URL1 = "127.0.0.1<seq2seq4repair_space>-<seq2seq4repair_space>-<seq2seq4repair_space>[08//Jan//2003:07:03:54<seq2seq4repair_space>-0500]<seq2seq4repair_space>\"GET<seq2seq4repair_space>//addrbook//<seq2seq4repair_space>HTTP//1.1\"<seq2seq4repair_space>200<seq2seq4repair_space>1981" ; private static final String URL2 = "127.0.0.1<seq2seq4repair_space>-<seq2seq4repair_space>-<seq2seq4repair_space>[08//Jan//2003:07:03:54<seq2seq4repair_space>-0500]<seq2seq4repair_space>\"GET<seq2seq4repair_space>//addrbook?x=y<seq2seq4repair_space>HTTP//1.1\"<seq2seq4repair_space>200<seq2seq4repair_space>1981" ; public void testConstruct ( ) throws Exception { } public void testcleanURL ( ) throws Exception { } public void testcheckURL ( ) throws Exception { } } }

Fix:
if ( ! ( FILTER . isFiltered ( line , el ) ) ) {